Flat panel displays have become mainstream products in the market. More and more types of flat panel displays are being marketed. For example, liquid crystal displays (LCDs) and emissive flat panel displays are two types of flat panel displays. Liquid crystal displays may be divided into groups such as thin-film transistor liquid crystal displays (TFT-LCDs), twisted nematic (TN) LCDs, super-twisted nematic (STN) LCDs, and ferroelectric liquid displays (FLCDs). A liquid crystal display needs a back-light source in rear of display panel for emitting light to display the contents shown in front of the panel. However, the transmittance of liquid crystal display is only 10%. This is the reason why it is difficult to increase the brightness of liquid crystal display.
Emissive flat panel displays are superior to liquid crystal displays when it comes to the brightness of panels. The display principle of emissive flat panel displays is similar to that of traditional cathode ray tubes. They all utilize charged particles to impact a screen coated with fluorescent material for displaying information or graphics on that screen. Emissive flat panel displays are classified into various types such as field emission displays (FEDs), plasma display panels (PDPs), electroluminescent displays (EL displays), and organic light emitting diode (OLED) displays. Among those displays, field emission displays have many advantages, for example, high brightness, thin thickness, light weight, a wide range of visual angles, a wide range of operational temperature, little energy consumption and so on.
Instead of a single electron gun used in a traditional cathode ray tube, a field emission display uses a field emitter array which emits electrons by field emission. Presently, there are at least three kinds of field emitter arrays, respectively based on carbon nanotubes, nanometer scale diamonds, and zinc oxide nanopins. These kinds of field emitter arrays are manufactured mostly by chemical vapor deposition (CVD). However, it is necessary to use a great amount of chemical reagents for growing desired nanotip structures at high temperature. These chemical reagents may cause pollution or damage to the environment. In addition, the processes to manufacture the three kinds of field emitter arrays are complicated, and a lot of time would be needed. At the present time, environmental protection, energy saving and high efficiency are highly emphasized. Therefore, there is a need to develop a method to overcome the above-mentioned disadvantages.